In some geographic areas it is difficult for trees and shrubs to receive water and fertilization naturally, due to the ground conditions.
For example, ground such as cohesive soil or other impermeable ground, which may comprise clay for example, require special watering and fertilization in order to achieve desirable growth. Climate conditions, such as those found in arid environments also contribute to natural watering difficulties. U.S. Pat. No. 6,540,436 and KR2074043 relate to such issues.